1. Field of Invention
This invention relates to airbag inflators, and more particularly to an airbag inflator and module suitable for rapidly inflating a passenger side airbag while mitigating injury to an out-of-position occupant located close to the instrument panel at the time of airbag deployment, and for minimizing the particulate released into the passenger compartment from the venting gases.
2. Description of the Prior Art
Until now the major effort in airbag system design has been toward airbags for the driver side of the motor vehicle. These systems typically include three elements: an accelerometer sensor for sensing the acceleration of a motor vehicle, an inflator responsive to the acceleration sensor and which generates an inflating gas, and an inflatable bag coupled to the inflator with vent holes in the bag. The inflators of these types of systems are single stage inflators which generate a large volume of gas in a very short time. Venting of the gas is accomplished by vent holes in the bag which become effective only after the airbag has completely unfolded. These systems are well suited for the driver side because the position of the driver is known and therefore the bag can be shaped and positioned so that it inflates quickly during the crash to protect the driver without injuring him. Single stage inflators are also well suited for the passenger side on relatively large cars having a soft body. However these types of inflators are too slow for small cars having a stiff body wherein the deceleration propagates to the passenger compartment faster than in a large car. Moreover if a single stage inflator is speeded up, it deploys the airbag out too quickly so that it may injure the passenger especially if the passenger is out of position. In addition, venting through the airbag does not provide pressure relief for an out-of-position passenger close to the instrument panel.